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Discussion Starter · #1 ·
Throughout the year, I have had problems with supposedly one of the easiest plants to grow --Rotala sp Green. Although increasing iron/traces seemed to be the solution last year, I can't seem to replicate the same results this year. Here are the aquarium conditions:

20g long
currently 6.15 wpg PC (2x55w PCs + 1x13w PC)... I'm experimenting. :)
Symptoms actually became WORSE when temporarily switched to 2x20w NO Flos for a week (2 wpg)
Pressurized CO2 being used... CO2 triple checked to be ~30ppm
NO3: ~5-10 ppm
PO4: ~1-1.5 ppm
Flourish 3 mL daily, Flourish Trace 3 mL daily, Flourish Iron 3 mL daily = 3x7= 21 mL of each supplement every week (that should be enough!!)
GH: 9
KH: 6
No additional K+ supplementation

Symptoms: Rotala sp Green produces small leaves which curl downward and corkscrew slightly. Older leaves are very dark green. Rotala sp Nanjenshan produces very short, scanty leaves with brown dead spots of necrosis.

Plants like Blyxa japonica, Tonina fluviatilis, H. zosterifolia, Ludwigia arcuata grow well without any sign of deficiency.

I will post pictures of the symptoms in a few hours.

Carlos


Here's a picture showing the Rotala sp Green. Notice the curled growth.


Close up of a stem showing the deficiency.


Individual stem.


Rotala sp Nanjenshan. The plant isn't as "fluffy" as it should be, grows slowly, and has many dead brown spots at the internodes and along the stems.
 

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Discussion Starter · #3 ·
I think the yellow color of the plants is partially due to the 9325k PC bulb I have in there mixed in with the 6700k. 9325k bulbs are HORRIBLE at rendering color (CRI in the 60s).

Someone emailed me suggesting that I raise NO3 levels and double check CO2 levels. I have tried raising NO3 levels and after a couple weeks of the high NO3 levels, I noticed no noticeable change in the plants. However, I am willing to try again...

I can't raise my CO2 levels any higher at this point. Even a slight turn of the CO2 knob will cause my fish to show visible signs of stress.

More iron/Fe?

As a little experiment, I dosed extra calcium today, raising my GH/KH by 1dGH. I'll report back if I see even the slightest improvement by the end of the week.

Carlos
 

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Discussion Starter · #5 ·
I've only had the current lighting up for about three days. The problem dates back way, way before I ever even thought about popping in a pair of power compacts. I will try the higher NO3s again.

I test my tank water twice a week. I formerly used an AP test kit. I am currently using the Red Sea test kit with good results as far as I can see. If I dose more, the test kit reads more nitrate. Dose less, it reads less... etc.

Carlos
 

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Discussion Starter · #18 ·
Ok, it's been 5 days since I've increased NO3 levels. There have already been some major changes in the morphology of several plants. My "purple strain" Limnophila aromatica has tranformed from a beautiful lilac color to lime green. My Ludwigia arcuata is now orange. The Rotala sp Nanjenshan has shown signs of new, healthy growth (about an inch so far). On the flip side, the Rotala macrandra 'narrow leaf' grew very large leaves in the beginning of the week but has since begun stunting.

Most importantly, although the internodes and growth rate of the Rotala sp Green have both increased tremendously, the leaves are still small and curved downward like in the photo. Some stems have stunted even more, showing some transparent patches on the newest leaves along with the twisting.

Is Rotala sp Green really so nitrate demanding? My usual nitrate indicators --Micranthemum umbrosum, Hottonia palustris, and Heteranthera zosterifolia --grow very large, lush, deep green leaves in all the conditions I've tried growing Rotala sp Green in.

Rotala sp Nanjenshan is recovering? Still looks yellowish. Then again, all my green plants look yellow under the 9325k bulb.


One of my nutrient indicators. Showing very large foliage.


Rotala sp Green still looks horrendous, although growth has quickened and the plant is shooting out many, many sideshoots.


The entire tank has lost a lot of "sparkle" and seems "dirty." A lot of the bottom portions of the plants show considerably amounts of algae.


Carlos
 

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Discussion Starter · #22 ·
Shawn,

All my plants pearl heavily, including the Rotala sp Green. It really is a poor indicator of plant health. I've tried growing Rotala sp Green under 6700k+9325k bulbs and under URI Aquasun/Coral Life Trichromatic NO bulb combinations. No luck.

It's not CO2, either. I've discounted NO3 as well. It has increased in growth rate, but it still looks as bad as ever.

No surface scum before increasing the light. After increasing the lighting, I did start to get some surface scum. That's not it either.

Carlos
 

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Discussion Starter · #25 ·
Jeff,

It would be interesting to note that soft water does have an effect on the Rotala genus. I've grown Rotala sp Green (along with macrandra, wallichii, wallichii 'long leaf', sp Nanjenshan) at home with great success. By home I mean south Florida, where the water hardness is KH 4, GH 5.

My nutrient levels were similar. I actually dosed a little less macro and micro nutrients into the system I had there --pretty lean. :)

Carlos
 

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Discussion Starter · #27 ·
I tried tripling the amount of KNO3 I was dosing for about two weeks and then stopped. The tank was obviously crashing (hard) due to an explosion of algae of three different sorts, and the Rotala sp Green was not looking not one bit better after two weeks (was growing fast...but the health of the new growth was really bad). I pulled the plug and sold the entire setup.

Is algae related to the Rotala sp Green problem I had? Nope. My Rotala sp Green was stunting just as badly when I took my photos for the ADA contest when there was near zero algae in the tank. Increasing and decreasing my iron/micronutrient dosing did not help nor did shifting around my phosphate levels. either. Increasing CO2 by even a tad led to gasping fish in the morning.

I KNOW it was not due to lighting, CO2, nitrate, phosphate, or iron.

I haven't tried growing it in softer water, yet.

Carlos
 

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Discussion Starter · #34 ·
I like to use Micranthemum umbrosum as my nitrate indicator, actually. Throughout the entire time that the Rotala sp Green was limping along, the M. umbrosum was producing very impressive foliage up to 1" wide (cS can attest to that with the specimens I sent him a few months ago).



I don't think it is iron... not when I was dosing about 3mL of Flourish AND 3 mL of Flourish Iron daily (21mL of each every week!).

Side note: I tried increasing this dosing amount, actually, but ended up with a lot of dead amano shrimp. I was dosing 6mL of each daily. So, amano shrimp are sensitive to iron but you have to dose A LOT to kill them... :oops:

Fish were oblivious/unharmed.

Carlos
 
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